UPDATE 1-TNK-BP head of upstream to leave company-sources


* Highest ranking exec to leave since shareholders fell out

* BP may sell TNK-BP stake to Rosneft, AAR may stay or sell

* Dodds unlikely to join colleagues at Rosneft

* Deputy seen as likely successsor

(Adds background on Dodds, likely sale of shareholders' stakesin TNK-BP)

MOSCOW, Oct 11 (Reuters) - The head of upstream at Russianoil firm TNK-BP will leave the company, thehighest-ranking executive to depart in an exodus of staff as apotential sell-off by its main shareholders looms, sources closeto TNK-BP said on Thursday.

Alexander Dodds joined TNK-BP from ExxonMobil Qatar ,where he had served as president, in October 2011. The sourcessaid his resignation would be announced to company staff onFriday.

Senior TNK-BP staff, including its top oil trader and headof mergers and acquisitions, have left the company in the monthssince BP and its partners in the Russian-British oil companysaid their 50-50 joint venture was untenable.

Both sides have said they are willing to sell out, thoughthe quartet of Soviet-born billionaires who share control of theNo.3 Russian oil producer have also said they would be willingto buy out the British oil major.

Russian state-backed oil firm Rosneft has said itwould like to buy out BP and is seeking financing for the deal,likely to be worth a total of $25 billion or more, though a fullmerger of TNK-BP and Rosneft through a buyout of both partnerscould be difficult to finance.

Dodds is seen as unlikely to join a steady flow ofexecutives from TNK-BP and BP itself to Rosneft, however.Sources close to TNK-BP said his likely successor was hisdeputy, Nikolai Ivanov.

(Reporting by Melissa Akin and Vladimir Soldatkin; Editing byMegan Davies and Mark Potter)

((melissa.akin@thomsonreuters.com)(+7 495 775 1242)(ReutersMessaging: melissa.akin.thomsonreuters.com@reuters.com))